DESCRIPTION: (Applicant's Abstract) Evidence for the utility of marijuana as an antiemetic drug is largely anecdotal. Given that marijuana is the most widely abused illicit drug (SAMHSA, 1996), there are great concerns about its therapeutic use. A primary concern is whether or not it is effective. A second concern is that use of marijuana in a clinical context by non-drug-abusing patients could lead to abuse of the drug outside of this context. Both of these issues have yet to be adequately addressed and are the focus of this proposed research. The antiemetic effects of marijuana will be explored in two placebo-controlled studies using two methods of inducing emesis in healthy volunteers. In Study 1, emesis will be induced via the chemoreceptor-trigger-zone by administering the dopamine agonist bromocriptine. In the second study, motion sickness will be induced. Subjects will smoke placebo or active marijuana prior to emesis induction. The profile of behavioral and subjective effects including ratings of nausea, drug liking, wanting more, and euphoria will be compared across drug conditions to determine: i) the antiemetic efficacy of marijuana and ii) how the presence of an aversive event such as nausea may modulate the pleasurable/euphoric effects of marijuana.